Very smart co-workers and the potential to be part of building software that solves a specific problem on a scale that nobody else on Earth has attempted.
Bingo. If you actually like CS, instead of just seeing programming as a way to get a fat paycheck like so many seem to, why would you not want to be part of FAANG or some other company building cutting-edge products and work on building some of the most advanced systems in the world?
Some people may not enjoy the "making the world an objectively worse place" part. Not everyone is moved only by a fat paycheck and working on interesting problems. Otherwise we might as well assume it is perfectly fine to work on a poison gas that only works on ethnicity X -- after all the pay might be pretty good, and it's a cutting-edge, advanced biochemical problem.
Obviously not saying FAANGs are quite that bad, but still, this is a pretty shallow reason to work somewhere.
Smart (in the usual understanding of smart), or good programmers (in the "can invert a binary tree on a whiteboard" sense)? These are two measures that are basically orthogonal.
Is there any evidence of that? Google selects people based on entirely different criteria, and promotes them for moving a button in Gmail from an inconvenient location to an even less convenient one.
Might depend on your definition of "intelligent" though. I've met quite a few, too, including friends and relatives. Sure, they better than average programmers, but general intelligence seems to be the same as in your general college educated population. Otherwise we'd be arguing that Damore (or, say, Altheide, if one has ideological preference for one or the other) are also "very intelligent".